1. Field of the Invention
The present invention relates generally to improvements in or relating to apparatus for transporting materials. More particularly, the present invention relates to apparatus for transporting of materials on conveyer rollers, which rollers are arranged on roller shafts which are journalled, one behind the other, laterally in a support member, and wherein several roller shafts are driven by a common drive unit, with each roller shaft being furnished with a member capable of transferring torque, and whereby the transporting of the material is effected by way of friction contact.
In general, there are utilized support members at both ends of the roller shafts, however, this is not always required and the conveyer rollers, arranged on the roller shafts, extend between the support members.
2. Description of the Prior Art
Apparatus for transporting of materials are furnished either with a positive drive or, as is contemplated in this specification, with a drive including friction contact. Thus, the transport of the material is in conformity with the friction value which results from the sum of the individual values of the parts or components involved. Transporting of the material is only carried out when the path is clear. According to the present state of the art this is achieved thereby that the conveyer rollers are connectible to the roller shafts only by way of friction contact, i.e. as required, they can rotate with respect to the roller shafts. The roller shafts, in turn, are positively connectible to a drive unit, which usually includes chain or sprocket wheels which are laterally supported at the support member. Motive force is provided by short chains extending from sprocket to sprocket, whereby for each roller there are required two sprocket wheels to be arranged alongside one another, or the motive force can be imparted by means of a continuous chain. In like manner, the drive may include a belt or belts with tooth-like projections.
In the event that there occurs in such prior art apparatus an undesired accumulation, leading to deceleration of the velocity of the equipment, the conveyer rollers continue to rotate with respect to the roller shafts. There does then substantially occur no relative movement between the conveyer rollers and the material to be transported, whereby damage to the material is avoided.
It is of disadvantage then, however, that this so-called friction-drive is relatively inaccurate, such that, that the transport of material is not always carried out without disruptions. For example, further conveying may be disrupted when material is laterally lodged against some projection. Furthermore the friction conditions vary in response to changes in moisture, degree of cleanliness, temperature and the like. In addition, the friction-drive is dependent upon the weight of the material to be transported, such that, generally, the apparatus would only be suitable for transporting materials of uniform mass.